Electric switch



April 5, 1949.

Filed July 30, 19,46

w,l J. culrl-lBERTSCJN Erm.

ELECTRXC SWITCH 2 Shasta-Sheet l Qld) (Tf a) Their Ati', @V may.

Plil 5, 1949- w. J. cUTHBERTsoN ETAL 2,466,388

ELECTRIC SWITCH Filed July so, 194s z sheets-sheet 2 Fig. f2s a* L15 il Patented Apr. 5, 1949 UNITED STATES PATENT OFFICE Schell, Jr., Lenox,

Mass., assignors to General Electric Company, a corporation of New York Application July 30, 1946, Serial No. 687,200

2 claims. l

Our invention relates to improvements in electric multiple terminal interconnecting switches and more particularly to improvements in such switches for connecting the winding terminals of three-phase electrical apparatus in series-Wye, series-delta, parallel-Wye or parallel-delta.

For changing the terminal connections of polyphase electrical apparatus such as the windings of power transformers so as to obtain various voltages, the windings may be connected in series-Wye, series-delta, parallel-Wye or parallel-delta. For this purpose, terminal boards with selectively connected jumpers, and the like have been generally used. These, however, are awkward, inconvenient and subject to erroneous connections especially when relatively frequent changes are necessary as in mobile power stations. To connect existing forms of switches with the terminal boards for establishing the different connections, although this might be convenient and dependable for quick changes, would result in too large a transformer unit particularly for a multiplicity of voltages and especially so since it is desirable to have the switches mounted within the transformer housing. Minimum space, however, is one of the fundamental requirements of a mobile power station. This requirement is in a measure incompatible with the connection requirements especially for a multiplicity of voltage ratios.

An object of our invention is to provide an improved electric multiple terminal interconnecting switch which is particularly adapted for connecting the windings of three-phase apparatus in series-Wye, series-delta, parallel-Wye or parallel-delta. Another object of our invention is to provide a compact series-parallel Wye-delta switch which requires a minimum of space and yet has the necessary terminal insulation level. A further object of our invention is to provide an improved high voltage series-parallel wyedelta switch which can be readily mounted within a transformer casing. These and other objects of our invention will appear in more detail hereinafter.

In accordance with our invention, we provide an electric multiple terminal interconnecting switch comprising juxtaposed and aligned sets of a plurality of movable terminal members and having each member provided with a stationary switch contact together with an aligned switch rotor having juxtaposed switch blade members operable to one circuit controlling position to establish an electric current conducting connection between certain terminal members in each set and a predetermined terminal member of the set and to another circuit controlling position to establish an electric current conducting connection between said predetermined terminal member and another terminal member of the set. Further in accordance with our invention, we provide a plurality of electrically interconnected terminal members, one for each pair of the sets of a plurality of terminal members, together with a second aligned switch rotor havlng juxtaposed switch blades with lateral offsets operable to one circuit controlling position to establish an electric current conducting connection between one of said predetermined terminal members of one set of each of the pairs of sets of a plurality of terminal members and the respectively associated terminal member of the plurality of interconnected terminal members and to another circuit controlling position to establish an electric current conducting connection between said one of said predetermined terminal members of the one set of a pair of a plurality of terminal members and the corresponding terminal member of the other set of the pair.

Our invention will be better understood from the following description when considered in connection with the accompanying two sheets of drawings, and its scope will be pointed out in the appended claims.

In the accompanying drawings, Fig. 1 is an elevation of an electric switch embodying our invention; Fig. 2 is a sectional and elevational view on the line 2-2 of Fig. 1; Fig. 3 is a perspective view of a part of the embodiment of our invention shown in Figs. 1 and 2; Fig. 4 is a circuit diagram illustrating the connections of a. three-phase multiple winding power transformer to the terminals of a switch embodying our invention with the movable circuit controlling elements of the switch in position to establish a parallel-delta connection of the transformer windings; and Fig. 5 is a circuit diagram similar to Fig. 4 with the movable circuit controlling elements of the switch in position to establish a series-Wye connection of the transformer windings.

In the accompanying two sheets of drawings, we have illustrated an embodiment of our invention in an electric switch adapted for interconnecting, for example, the output windings of a three-winding three-phase power transformer i, shown only in Figs. 4 and 5, in series-Wye, series delta, parallel-Wye or parallel-delta. As shown, the transformer I, comprises phases A.

a and C, phase A having windings a-h and e-f; phase B having windings o-h, i-i, and k-Z; and phase C having windings riz-n, o-qJ, and 1 -r. In Fig. 4, the switch is shown in the parallel-delta connecting position, and in Fig. 5, the switch is shown in the series-Wye connecting position. While switches embodying our invention are especially applicable to a polyphase multiwinding transformer, it is to be understood that such switches may also be used with a plurality of single winding polyphase transformers.

In the illustrated embodiment of our invention, we have shown an electric switch comprising six juxtaposed sets ci four planar spaced stationary contacts 2, 3, 4 and 5 which are respectively mounted on the aligned high voltage insulators 6, l, 8 and t provided with terminals designated by lower ease letters corresponding to the designations oi the terminals of the transformer windings as shown in Figs. 4 and 5. In the illustrated embodiment of our invention, each of the four planar aligned stationary contacts is provided with a pair of pivotally and resiliently mounted jaw type contact elements I shaped at the ends to provide line contact and limited against turning about their pivotal axes by stops I2. The insulators 6, l, 8 and 9, as shown, are suitably secured in vertical alignment to a channel shaped base I3 of suitable material. This base is supported from side members I4 which are cross connected by a framing element I and a through bolt I6, broken away in Fig. 1 for clearness. Also, as shown, the side members I4 are perforated for free circulation of the insulating uid in the transformer. For mounting the assembly, brackets II secured to the side members I4 are provided.

In accordance with our invention, we provide for each set of four stationarycontacts 2, 3, 4 and 5 a movable circuit controlling member I8 which is aligned so as to be operable to one circuit controlling position, the parallel connecting position shown in Figs. 1, 2 and 4, to interconnect the three contacts 2, 3 and 5 and to another circuit controlling position, the series connecting position shown in Fig. 5 and in dotted lines in Fig. 2, to interconnect the contacts 3 and 4. As shown, the circuit controlling member I8 is of the double blade type with a central annular contact portion I9 which continuously engages the contact 3, a blade extension which is movable into engagement with the Contact elements IIJ on the contact 2 and a blade extension 2I which is movable into engagement with the contact elements I0 on either the contact 4 or the contact 5.

In order to have the six circuit controlling members I8 simultaneously movable, they are mounted on a rotor shaft 22 which is journaled in the side members I4. Each of the circuit controlling members I8 is rigidly secured to an insulator 23 so as to turn therewith, and the insulators 23 are rigidly secured to the rotor shaft 22 so as to turn therewith. For turning the rotor shaft 22, it is provided, as shown, with part of a jaw coupling 24 which is engageable by the other half of the jaw coupling arranged to be operated from outside of the transformer tank, as will be obvious to those skilled in the art.

Further in accordance with our invention, we provide a iifth or auxiliary stationary contact 25 for each pair of adjacent sets of four stationary contacts 2, 3, 4 and 5 so that in cooperation with these sets, delta and wye connections are available with either series or parallel connections. As shown, each of the three juxtaposed auxiliary contacts 25 is provided with jaw contact elements I@ similar to those provided for the contacts 2, 3, 4 and 5. The contacts 25 mounted on a connecting bus 26 which is supported on two insulators' 2l. These insulators are mounted on brackets 28 secured to a flange of the base I3. Also, the bus bar 26 is provided with a grounding terminal 29. In accordance with our invention, we provide for each of the contacts 25 a cooperating movable circuit controlling member 30 which is operable in one circuit controlling position, the delta position shown in Figs. l, 2 and 4, to interconnect one of the four stationary contacts 2, 3, 4 and 5, such as 2, of one set with the corresponding contact 2 in the adjacent set and in another circuit controlling position, the Wye position shown in Figs. 3 and 5 and in dotted lines in Fig. 2, to interconnect the contact 2 of the adjacent set of four contacts on the right with the associated fifth contact 25. As shown, the cooperating circuit controlling member 30 is of the double blade type with a blade extension 3I which is movable into engagement with either the contact 2 of the left-hand set of pair of adjacent sets of four stationary contacts or the contact -25 associated with such left-hand set. Also, the cooperating circuit controlling member 30 is provided with a laterally oiset blade extension 32 projecting substantially perpendicularly from the blade extension 3I and carrying a relatively long contact block 33 which is continuously in engagement with the contact 2 on the right-hand set of a pair of adjacent sets of contacts.

In order to have the three cooperating circuit controlling members 30 simultaneously movable, they are mounted on an auxiliary rotor shaft 34 which is journaled in the side members I4. Each of the cooperating circuit controlling members 3l) is rigidly secured to an insulator 35 so as to turn therewith, and the insulators 35 are rigidly secured to the rotor shaft 34 so as to turn therewith. For turning the shaft 34, it is provided, as shown, with part of a jaw coupling 36 which is engageable by the other half of the jaw coupling arranged to be operated from outside of the transformer tank, as will vbe obvious to those skilled in the art.

Assuming the parts positioned as shown in Fig. 1 and as shown in full lines in Fig. 2, then the transformer connections are parallel-delta, as will be apparent from the circuit diagram shown in Fig. 4 wherein the windings a-b, c-d, e-f of phase A and the windings g-h, i-j, k-l of phase B and the windings m-n, o-p, q-r of phase C are connected in parallel in each phase and the respective phases are connected in delta. If it is desired to change from the delta-parallel connection to the Wye-parallel connection, then the shaft 34 is turned counterclockwise until the cooperating circuit controlling member 30 is in the position shown in Fig. 3 and in dotted lines in Fig. 2. During this movement, the blade member 3I is moved from the contact 2 of the lefthand set of a pair of sets of four stationary contacts 2, 3, 4 and 5 to the contact 25 associated with the set while the blade projection 32 through its block 33 remains in contact with the contact 2 of the adjacent set of four stationary contacts. During this counterclockwise movement of the cooperating circuit controlling member 30, the phase connections are changed from delta to wye.

If it is desired to have a series-Wye connecassesses tion, then from the position shown in i. and 4 in solid lines in Fig. 2 both of the snaits 22 and 35 are turned ceunterolooewise to the position shown in Fie. 5 and in nottea line in Fig. 2. The phases are new connected in Wye and the windings of each phase are conne E position shown in Fig.' 2 thereby eonneotine the phase windings in delta.

In the circuit diagrams shown in 5, it is to oe understood that the nais a, m and g are the line termin. cated `oy the designation Line While We have shown end describen enf: vention in considerable rieteily We do not 'i' to se imited to the exact arrangements s 11 but seek to @over the appendeei elaiins n tno-se modifications that ieil within the true s scope of inventiona What We Claim is new desire t Letters i-fefent of the United States i. An eieetrie innltipie termi ing switch comprising a plurality of in sets of aligned terminal members navo@ 'm member provided with a stationery tact, a iirst .switcie` rotor having j.

double blades, each in aiegnrnent for in one angniar position of seid Totes' m corresponding stationary swten conte correspendng -termine set to establish eiee trie entrent conducting eonnectien ne n two terminal members in said set enti a minal member of the set and in stationary switch contacts to este'loi tric current conducting conneetien ueen one of said two terminal members and ter minet member or" -the set, e plurality f eieetri cally interconnected auxilensyA stationair switch contacta each in alignment with eeen pair of adjacent sets of teffminai n 1ersY e. second. switch rotor leaving is offset blaoles operable to one eireut oon eosition for engaging with the eorresgnene stef tionary switeivI contacts to est/enlist@ estrie current conducting eonneeton between third terminal member of alternate sets oi" ter minal members and the eorresoor e one of 50 said interconnected auxiliary stati :r Seite contacts and te another eironit oontroiiinlg new sition for engaging with the oorresponding stetionary switch contests to establish. an electric curr-ent conducting connection sani, third termine! members ot eeen pair of eejeeent of terminal members tor in A combinent series-parallel delta-Wye inter connecting switch coznprisinsr six juxtaposed sets of met, second., third and fourth terminal members in planar alignment and having one end of the fourth member projecting beyond the enrresponding ends of the other three members and said ends oi each member provided with e, stationary switch Contact and the said end of the first member of each set provided with an auxiliary lateral stationery switch contact, u rst switch rotor having an axis extending oneosite the second terminal member of each set and provoer with sin juxtaposed nflnltieleeennl test eine s, centrally mounted on, the ro-n rner elgmnent for engaging in one oosition of the rotor with the irst, see nelg ionrth stationary switch contests of e, orresmnding terminal set to establish naselle. electric currentoonducting connections there@ between and for engaging in anotlfnnu angular position saisi rotor with the second and third stationery switch contacts in the set to estan'A lien series eieetrie current eonclucting. connes-- tion therebetween, three electrically nteiconm neeteei stationary switch contacts, eeen in sneeeeiwa'oert planer alignment with the enxil iary sentant o the first terminal member oi e eeresnonring one of each pair of adjaeent sete erminal membersI7 end a vsecond switch rotor ,t juxtaposed multiple contact oset biz-nies, eeen eignei for engaging in one angueositon oi said seeond rotor with the eis-amb lary contests oi' the :ist terminal member oi" e corresponding pair of adjacent sets of terminal members to establish e delta current conducting connection therebetween and for engaging' in en other enguar position of said second rotor with e. oerresnondng one of said electrically inter eonneeteoi auxiliary stationary switch contests the amnliery Contact of the rst member of tine other of each nais of adjacent sets of termi nel members to estalsiish a wy@ current sonriente@v ine connection therebetween.

REFERENCES @ETRE The following references are o reeor'i in @le of patent:

UNTED STATES PATENTS 

